Wondering if you could possibly assist me in a diagnosis for my 4t65e m15? Apologies for such a lengthy email, figured the more info you have the better off, if you could assist in any way I’d greatly appreciate it and possibly start ordering parts lol. Not sure if original trans but car has 173k, its had codes P0716/717/730,and 1860 for almost a year it ran perfectly minus kick down issues, fluid aged but not horrible, usually car sat at 160’f and one day when it was -30 out it started going to normal op temp around 185, ran like that for a week just figuring luck but now thinking trans temp, got tcc issues getting on interstate started slipping periodically at high speeds rest of the day but nothing horrible, next day I drove it 50 miles and it progressively got worse, fluid has slight smell but seen worse, threw in Lucas and reset pcm. From there fhe main issue popped up, trans stopped slipping immediately but lost r/1. Reverse engages, car moves a couple feet and it stops will load tc up to 3k rpm and do nothing, does free roll backwards. Park/neutral had delayed release with a surge forward then releases but car would slightly creep forward if revved. 1st gear feels bound, same issues as R essentially, wheels seem locked, 3k stall, but it moves forward like its dragging the titanic. Seems as if 2nd clutches are seized? (I'm a complete trans amateur so just guessing, hoping to attempt first repair).as soon as I select m2 it is completely free and moves without issue instantly. D is second start obviously. Week later added another Lucas, 2-4 even with supposed solenoid codes runs like its almost new kickdown even works again. Still no difference on r/1. I've spent like 3days browsing google trying to pinpoint exactly the issue but it seems everyone else has similar issues but not all the same ones I’m having, trans runs perfectly cool too. Later I’m going to disassemble the reverse servo and also check the R band while I have access to check it’* condition. Already tried linkage, tried fuses, checked pcm side harnesses so far, replaced B+ cable to fuse panel due to being 99% corroded figured maybe low power to solenoids, but of course nothing’* that easy lol. So, assuming internal cross leak or seized clutches? Not bothering wasting my time or money in flush and filter. Nervous to attempt repairs but willing to do full rebuild if need be but I’m really hoping valve body/sensor upgrades, and a good flush will bring back my other gears.